The present invention relates to pressure-sensitive adhesive composites having a delivery system and methods of using the composites as well as methods of manufacturing the composites. In particular, the present invention is useful in connection with very thin high moisture vapor permeable film wound dressings.
The use of transparent film dressing continues to grow at an accelerated rate. In addition to their use as protective layers over wounds, where they facilitate healing in a moist environment while acting as a barrier to contaminating liquids and bacteria, the films are also used over catheters to prevent contamination of the catheter insertion site by contaminating liquids and bacteria. The films may also be used as surgical drapes because of their barrier properties. Dressings and drapes fitting the above description are available under a number of trade names such as TEGADERM(trademark) (3M Company, St. Paul, Minn.), BIOCLUSIVE(trademark) (Johnson and Johnson Company, New Brunswick, N.J.), OP-SITE(trademark) (T.J. Smith and Nephew, Hull, England), and UNIFLEX(trademark) (How Medica, Largo, Fla.).
The polymeric films used in those dressings and drapes, referred to as dressings below, are typically conformable. In other words, the films are extremely flimsy, flexible, and supple. They are typically supplied with a releasable protective liner covering the adhesive coated surface of the film. When the liner is removed, the adhesive coated film tends to wrinkle and adhere to itself, interfering with the smooth aseptic application of the dressing to a patient""s skin. Various delivery systems have been proposed to address this problem.
U.S. Pat. No. 5,153,040 (Faase, Jr.) discloses dressing delivery systems in which a two-part liner is provided to protect the pressure sensitive adhesive on the bottom face of the film. Each liner includes an adhesion enhancement strip which is preferably permanently affixed to the pressure sensitive adhesive and film backing. During delivery, the adhesion enhancement strips are separated from the remainder of the film along perforation lines on opposite ends of the dressing. One disadvantage with this process is that it requires additional components, i.e., the adhesion enhancement strips located between the liner and the film, to accomplish the delivery system. Those additional components add to the cost and complexity of manufacturing the dressings.
U.S. Pat. No. 4,513,739 (Johns) discloses dressing delivery systems which also include a two-part liner and means for retarding weakness of the release liner from the adhesive on the film at opposite ends of the dressing. Like the delivery system described above, however, this system also requires the addition of components to the dressing to provide the differential release characteristics at the ends of the dressing. Among the additional components are different adhesives, backings with varying layer thicknesses, additional layers secured to the backing, folds in the liner such that the liner is directly connected to the backing over the ends of the dressing (see FIG. 5), and additional components added to the ends of the dressing that attach the liner to the backing (see FIG. 6). As above, the additional components add to the cost and complexity of manufacturing the dressings.
U.S. Pat. No. Re. 33,353 (Heinecke) discloses a dressing delivery system in which the liners are strip-coated with a release agent such that the ends of the liners are free of release coatings, which increases their adhesion to the pressure-sensitive adhesive on the bottom face of the backing. As a result, the backing can be suspended between two liners during delivery. After delivery, the end portions of the backing are preferably removed along with the attached liner. One disadvantage with this approach is that the strip-coated liner material must be stocked separately from liners in which the entire surface includes a release coating, thereby adding to the cost of manufacturing the dressings.
The present invention provides adhesive composite dressings with simple and inexpensive delivery systems. The dressings include liners having a release surface and a retention surface. The bond strength between the liner and the pressure sensitive adhesive in the area of the retention surface is greater than the bond strength between the liner and the pressure sensitive adhesive in release surface. The increased bond strength in the area of the retention surface allows the backing to be held taut during delivery to assist in smooth aseptic delivery of the dressing. The retention surfaces can be provided by abrasion, embossing, perforating the liner, or combinations thereof.
Advantages of the delivery systems provided by the present invention include the simplicity and ease with which the dressings can be manufactured. For example, a standard liner with a fully coated release surface can be used with the retention surfaces being formed in-line during the converting process. As a result, no special liners are needed in inventory.
A further advantage of the notched dressings of the present invention is that the notched portions of the dressing are maintained in tension, thereby assisting in delivery of the notched dressings over catheter insertion sites.
In one aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a liner comprising a release surface and an abraded surface, wherein the abraded surface is attached to the pressure sensitive adhesive along the first edge of the backing; and a handle attached to the backing along the second edge of the backing.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a first liner sheet including a first release surface attached to a portion of the pressure sensitive adhesive and a first abraded surface attached to the pressure sensitive adhesive along the first edge of the backing, wherein the strength of the bond between the first abraded surface and the pressure sensitive adhesive is greater than the strength of the bond between the first release surface and the pressure sensitive adhesive; and a second liner sheet including a second release surface attached to a portion of the pressure sensitive adhesive and a second abraded surface attached to the pressure sensitive adhesive along the second edge of the backing, wherein the strength of the bond between the second retainer and the pressure sensitive adhesive is greater than the strength of the bond between the second release surface and the pressure sensitive adhesive.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a liner comprising a release surface and a retention surface, the retention surface including a discontinuous release coating, wherein the retention surface is attached to the pressure sensitive adhesive along the first edge of the backing; and a handle attached to the backing along the second edge of the backing.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a first liner sheet including a first release surface attached to a portion of the pressure sensitive adhesive and a first retention surface including a discontinuous release coating, the first retention surface being attached to the pressure sensitive adhesive along the first edge of the backing, wherein the strength of the bond between the first retention surface and the pressure sensitive adhesive is greater than the strength of the bond between the first release surface and the pressure sensitive adhesive; and a second liner sheet including a second release surface attached to a portion of the pressure sensitive adhesive and a second retention surface including a discontinuous release coating, the second retention surface being attached to the pressure sensitive adhesive along the second edge of the backing, wherein the strength of the bond between the second retention surface and the pressure sensitive adhesive is greater than the strength of the bond between the second release surface and the pressure sensitive adhesive.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; and a liner including a release surface attached to the pressure sensitive adhesive and a void formed through the liner, the void exposing a portion of the pressure sensitive adhesive, wherein the bond strength between the liner and the pressure sensitive adhesive is increased proximate the void.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces and opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a first liner sheet including a first release surface attached to a portion of the pressure sensitive adhesive and a first void exposing a first portion of the pressure sensitive adhesive; and a second liner sheet including a second release surface attached to a portion of the pressure sensitive adhesive and a second void exposing a portion of the pressure sensitive adhesive.
In another aspect, the present invention provides an adhesive composite dressing including a backing having top and bottom faces, opposing first and second edges; a pressure sensitive adhesive located on the bottom face of the backing; a liner attached to the pressure sensitive adhesive; means for increasing the bond strength between the liner and the pressure sensitive adhesive proximate the first edge of the backing; and a notch formed in the backing, pressure sensitive adhesive, and the liner, wherein the notch opens along the first edge of the backing and extends towards the second edge of the backing.
In another aspect, the present invention provides a method of manufacturing an adhesive composite dressing by providing a backing having top and bottom faces; providing pressure sensitive adhesive on the bottom face of the backing; providing a liner having a release surface and at least one retention surface; and attaching the release surface and the retention surface of the liner to the pressure sensitive adhesive on the backing.
These and other features and advantages of the articles and methods of the present invention are discussed below.